"Test Case" by Andrew Plotkin.
A room has a number called the size.
The verb to measure (it measures, they measure, it is measuring) implies the size property.
The Kitchen is a room. The size is 3.
The Bathroom is a room. The size is 5.
When play begins:
if a room (called R) measures 3:
say "[R] is 3.";
if a room (called R) measures 5:
say "[R] is 5.";
say "But the size of the Kitchen is [the size of the Kitchen]."